Polyarylene sulfide and a preparation method thereof

ABSTRACT

The present invention relates to a polyarylene sulfide having more improved miscibility with other polymer materials or fillers, and a method of preparing the same. At least part of end groups of the main chain of the polyarylene sulfide is carboxyl group (—COON) or amine group (—NH2).

TECHNICAL FIELD

The present invention relates to a polyarylene sulfide having moreimproved compatibility with other polymer materials or fillers, and amethod of preparing the same.

BACKGROUND OF THE INVENTION

Now, polyarylene sulfide is a representative engineering plastic, andthe demand for the products being used in a high temperature andcorrosive environment or the electronic goods is increasing due to itshigh heat resistance and chemical resistance, flame resistance, electricinsulation, and so on.

Among the polyarylene sulfides, polyphenylene sulfide (PPS) is one andonly commercially on sale now. The commercial preparation process of PPSbeing applicable until now is the method of carrying out a solutionpolymerization of p-dichlorobenzene (pDCB) and sodium sulfide in a polarorganic solvent such as N-methylpyrrolidone. The method is known asMacallum process.

However, when the polyarylene sulfide is prepared by such Macallumprocess, a salt type by-product may be formed in a solutionpolymerization process using sodium sulfide, and thus there is adisadvantage of requiring a washing or drying process for eliminating asalt type by-product or a residual organic solvent. Furthermore, sincethe polyarylene sulfide prepared by such Macallum process is a powderform, the post processability and workability may decrease.

Accordingly, a method of melt-polymerizing the reactants includingdiiodoaromatic compounds and sulfur element was suggested as the methodof preparing the polyarylene sulfide such as PPS and the like. Suchmethod does not form a salt type by-product and not use an organicsolvent in the preparation process of the polyarylene sulfide, and thusit does not require an additional process for eliminating them.Furthermore, since the polyarylene sulfide prepared finally has a pelletform, there is an advantage of easy post processability and goodworkability.

However, in the case of the polyarylene sulfide prepared by themelt-polymerization method, the ends of the main chain were composed ofiodine and most aryl groups (representatively, benzene). Therefore,there was a disadvantage of that such polyarylene sulfide was inferiorin the compatibility with other polymer materials or all sorts ofreinforcements or fillers like glass fiber and the like due to thecharacteristics of its main chain structure.

Due to this, it was hard to compound the polyarylene sulfide prepared bythe melt-polymerization method with other polymer materials or fillersfor securing optimized properties suitable to various uses, and it wasdifficult to show optimized properties even if it was compounded withthem.

DETAILS OF THE INVENTION Objects of the Invention

It is an aspect of the present invention to prepare a polyarylenesulfide having more improved compatibility with other polymer materialsor fillers, and a method of preparing the same.

It is another aspect of the present invention to provide a shapedarticle including the polyarylene sulfide.

Technical Means

The present invention provides a polyarylene sulfide of which at leastpart of end groups of the main chain is carboxyl group (—COON) or aminegroup (—NH₂).

The present invention also provides a method of preparing polyarylenesulfide, including the steps of: polymerizing a reactant including adiiodoaromatic compound and sulfur element; and adding a compound havingcarboxyl group or amine group thereto while carrying out thepolymerization step.

The present invention also provides a shaped article including thepolyarylene sulfide resin.

Hereinafter, the polyarylene sulfide according to specific embodiment ofthe invention, the preparation method thereof, and the shaped articleincluding the same are explained in more detail. However, the embodimentis provided only for an example of the invention, and the scope of theinvention is not limited to or by them and it is obvious to a personskilled in the art that various modifications are possible in the scopeof the invention.

In this description, “include” or “comprise” means to include anycomponents (or ingredients) without particular limitation unless thereis no particular mention about them, and it cannot be interpreted as ameaning of excluding an addition of other components (or ingredients).

According to one embodiment of the invention, a polyarylene sulfide ofwhich at least part of end groups of the main chain is carboxyl group(—COOH) or amine group (—NH₂) is provided.

The present inventors accomplished the present invention, in the courseof studying the method of preparing a polyarylene sulfide having bettercompatibility with other polymer materials or fillers which can becompounded with various materials and can realize optimized propertiessuitable to various uses, in the process of preparing a polyarylenesulfide by melt-polymerizing a reactant including a diiodoaromaticcompound and sulfur element.

From the research of the present inventors, it is recognized that thepolyarylene sulfide prepared by prior melt-polymerization method has theends of the main chain composed of iodine and most aryl groups(representatively, benzene) and there is substantially no functionalgroup in the main chain, and thus there is a disadvantage of that suchpolyarylene sulfide is inferior in the compatibility with other polymermaterials, all sorts of reinforcements such as glass fiber and the like,or fillers.

However, it is recognized that the polyarylene sulfide of one embodimentshows good compatibility with other polymer materials or fillers, sincereactive functional groups such as carboxyl group (—COOH) or amine group(—NH₂) are introduced to at least part of the ends of the main chain ofthe same. Consequently, the polyarylene sulfide of one embodiment can besuitably compounded with various polymer materials or fillers, and makesit possible to provide a resin composition and a shaped article showingthe optimized properties suitable to various uses. Simultaneously withthis, the polyarylene sulfide can show good heat resistance and chemicalresistance, and excellent mechanical properties unique to thepolyarylene sulfide.

The polyarylene sulfide of one embodiment may show the peak of about1600 to 1800 cm⁻¹ derived from carboxyl groups of the ends of the mainchain or the peak of about 3300 to 3500 cm⁻¹ derived from amine group,in a FT-IR spectrum, when it is analyzed with FT-IR spectroscopy. Atthis time, the intensity of the peak of 1600 to 1800 cm⁻¹ or the peak of3300 to 3500cm ⁻¹ may correspond to the amount of carboxyl groups oramine groups connected to the ends of main chain.

According to one example, in the FT-IR spectrum of the polyarylenesulfide of one embodiment, if the height of the ring stretch peak shownat about 1400 to 1600 cm⁻¹ is assumed as the intensity of 100%, therelative height intensity of the peak of about 1600 to 1800 cm⁻¹ orabout 3300 to 3500 cm⁻¹ may be about 0.001 to 10%, about 0.01 to 7%,about 0.1 to 4%, or about 0.5 to 3.5%. At this time, the ring stretchpeak shown at 1400 to 1600 cm⁻¹ may be what is derived from the arylenegroup such as phenylene and the like included in the main chain of thepolyarylene sulfide. Since the height intensity of the peak of about1600 to 1800 cm⁻¹ derived from carboxyl groups or the peak of about 3300to 3500 cm⁻¹ derived from amine groups is about 0.001 to 10%, about 0.01to 7%, about 0.1 to 4%, or about 0.5 to 3.5% in comparison to the heightintensity of the peak derived from the arylene group (for example,phenylene group), the polyarylene sulfide of one embodiment can showgood compatibility with other polymer materials or fillers and canmaintain excellent properties unique to the polyarylene sulfide.

Meanwhile, the melting temperature of the polyarylene sulfide of oneembodiment may be about 265 to 290° C., about 270 to 285° C., or about275 to 283° C. Because of such melting temperature range, thepolyarylene sulfide of one embodiment obtained by melt-polymerizationmethod, to which carboxyl group or amine group is introduced, can showexcellent heat resistance and flame retardance.

And, the number average molecular weight of the polyarylene sulfide maybe about 5,000 to 50,000, about 8,000 to 40,000, or about 10,000 to30,000. The polydispersity index defined as the weight average molecularweight divided by the number average molecular weight may be about 2.0to 4.5, about 2.0 to 4.0, or about 2.0 to 3.5. Because the polyarylenesulfide of one embodiment has such polydispersity index and molecularweight range, it can show excellent mechanical properties andprocessability and can be processed into various shaped articles forvarious uses.

Furthermore, above polyarylene sulfide of one embodiment may have themelt viscosity of about 10 to 50,000 poise, about 100 to 20,000, orabout 300 to 10,000, which is measured with a rotational viscometer at300 ° C. The polyarylene sulfide of one embodiment having such meltviscosity can show superior mechanical properties in company withexcellent processability.

For example, the polyarylene sulfide of one embodiment may have thetensile strength of about 100 to 900 kgf/cm², about 200 to 800 kgf/cm²,or about 300 to 700 kgf/cm², which is measured according to ASTM D 638,and the elongation of about 1 to 10%, about 1 to 8%, or about 1 to 6%,which is measured according to ASTM D 638. Furthermore, the polyarylenesulfide of one embodiment may have the flexural strength of about 100 to2,000 kgf/cm², about 500 to 2,000 kgf/cm², or about 1,000 to 2,000kgf/cm², which is measured according to ASTM D 790, and the impactstrength of about 1 to 100J/m, about 5 to 50 J/m, or about 10 to 20 J/m,which is measured according to ASTM D 256. Like this, the polyarylenesulfide of one embodiment can show good compatibility with other polymermaterials or fillers and can exhibit excellent properties.

The polyarylene sulfide of one embodiment may show good compatibilitywith various thermoplastic resins such as polyvinylalcohol-based resins,vinylchloride-based resins, polyamide-based resins, polyolefin-basedresins, polyester-based resins, and the like; various thermoplasticelastomers such as polyvinylchloride-based elastomers, polyolefin-basedelastomers, polyurethane-based elastomers, polyester-based elastomers,polyamide-based elastomers, polybutadiene-based elastomers, and thelike; or various reinforcements/fillers such as glass fiber, carbonfiber, boron fiber, glass bead, glass flake, talc, calcium carbonate,and the like. Therefore, above polyarylene sulfide of one embodiment canbe compounded with other various polymer materials or fillers and showexcellent synergistic effect, and it becomes possible to realize theproperties optimized to various purposes.

As an example, it was recognized that the elongation was elevated about10 times from about 2.2% to about 25.2%, the impact strength waselevated about 3 times from about 17 J/m to about 54 J/m by compoundingabout 90 weight % of the polyarylene sulfide of one embodiment of whichcarboxyl group is introduced to the end group of the main chain, andabout 10 weight % of thermoplastic elastomer. Furthermore, it wasrecognized that the tensile strength was largely elevated from about 602kgf/cm² to about 1750 kgf/cm² by compounding about 60 weight % of thepolyarylene sulfide of one embodiment of which amine group is introducedto the end group of the main chain, and about 40 weight % of glassfiber. Therefore, it can be known from the improved properties caused bysuch compounding that the polyarylene sulfide of one embodiment can showgood compatibility with other various polymer materials or fillers, andconsequently can exhibit excellent synergistic effects.

When the polyarylene sulfide of one embodiment is compounded with otherpolymer materials or fillers, it is preferable to mix about 10 to 99weight % or about 50 to 90 weight % of the polyarylene sulfide and about1 to 90 weight % or about 10 to 50 weight % of one or more componentsselected from the group consisting of thermoplastic resin, thermoplasticelastomers, and fillers. A shaped article having excellent propertiespreferable to various uses can be prepared by shaping such mixture witha method of biaxial extrusion and the like.

Meanwhile, according to another embodiment of the invention, a method ofpreparing the polyarylene sulfide is provided. Such method of anotherembodiment may include the steps of polymerizing a reactant including adiiodoaromatic compound and sulfur element; and adding a compound havingcarboxyl group or amine group thereto while carrying out thepolymerization step.

In the preparation method of another embodiment, the compound havingcarboxyl group or amine group may be added thereto when the degree ofpolymerization reaction of the diiodoaromatic compound and sulfurelement is progressed about 90% or more, or about 90% or more and lessthan 100%, (for example, in the latter part of the polymerizationreaction), wherein the degree of polymerization reaction is determinedby the ratio of present viscosity to target viscosity. The degree ofpolymerization reaction can be determined as the ratio of presentviscosity to target viscosity. For this, an objective molecular weightof the polyarylene sulfide and a target viscosity corresponding to theobjective molecular weight are set up, and the present viscosityaccording to the degree of polymerization reaction is measured. At thistime, the present viscosity may be differently measured by a methodwell-known to a person skilled in the art in accordance with the scaleof reactor. For example, when the polymerization is carried out in arelatively small polymerization reactor, it may be measured by using aviscometer after taking a sample from the reactor where thepolymerization reaction is progressing. On the other hand, when thereaction is carried out in a huge continuous polymerization reaction,the present viscosity may be measured continuously in real time with aviscometer installed in the reactor itself.

Like this, the polyarylene sulfide of one embodiment of which carboxylgroup (—COOH) or amine group (—NH₂) is introduced to at least part ofend groups of the main chain can be prepared by adding and reacting thecompound having carboxyl group or amine group in the latter part of thepolymerization reaction of the reactant including the diiodoaromaticcompound and sulfur element. Particularly, since the compound havingcarboxyl group or amine group is added in the latter part of thepolymerization reaction, proper amount of carboxyl group or amine groupcan be introduced to the end groups of the main chain, and thepolyarylene sulfide of one embodiment having not only good compatibilitywith other polymer materials or fillers but also excellent propertiesunique to the polyarylene sulfide can be prepared effectively.

Meanwhile, in the preparation method of another embodiment, an arbitrarymonomer compound having carboxyl group or amine group may be used as thecompound having carboxyl group or amine group. As the examples of thecompound having carboxyl group or amine group, 2-iodobenzoic acid,3-iodobenzoic acid, 4-iodobenzoic acid, 2,2′-dithiobenzoic acid,2-iodoaniline, 3-iodoaniline, 4-iodoaniline, 2,2′-dithiodianiline, or4,4′-dithiodianiline may be used, and various compounds having carboxylgroup or amine group can be used in addition.

Furthermore, the compound having carboxyl group or amine group may beadded thereto in the amount of about 0.0001 to 5 parts by weight, about0.001 to 3 parts by weight, or about 0.01 to 2 parts by weight, based on100 parts by weight of the diiodoaromatic compound. Proper amount ofcarboxyl group or amine group can be introduced to the end groups of themain chain by adding such amount of the compound having carboxyl groupor amine group, and consequently, the polyarylene sulfide of oneembodiment having not only good compatibility with other polymermaterials or fillers but also excellent properties unique to thepolyarylene sulfide can be prepared effectively.

Meanwhile, in the preparation method of another embodiment, thepolyarylene sulfide is prepared basically by the method of polymerizingthe reactant including the diiodoaromatic compound and sulfur element,and consequently, the polyarylene sulfide having superior mechanicalproperties to prior Macallum process can be prepared.

At this time, the diiodoaromatic compound may be one or more compoundsselected from the group consisting of diiodobenzene (DIB),diiodonaphthalene, diiodobiphenyl, diiodobisphenol, anddiiodobenzophenone, but not limited to or by them, diiodoaromaticcompounds that alkyl group or sulfone group is connected to abovecompounds as a substituent or an oxygen or nitrogen atom is included inthe aromatic group may also be used. There are various diiodocompoundisomers of diiodoaromatic compounds depending on the position of iodineatoms, and a compound having iodine at para-position likepara-diiodobenzene (pDIB), 2,6-diiodonaphthalene, or p,p′-diiodobiphenylmay be used more preferably.

And, the form of sulfur element which reacts with the diiodoaromaticcompound is not limited particularly. Generally, sulfur elements existin a cyclooctasulur (S8) form in which 8 atoms are connected at roomtemperature. However, if not such form, any solid type or liquid typesulfur which can be used commercially may be used without particularlimitation.

Furthermore, the reactant may further include a polymerizationinitiator, a stabilizer, or a mixture thereof. As the polymerizationinitiator, one or more initiator selected from the group consisting of1,3-diiodo-4-nitrobenzene, mercaptobenzothiazole,2,2′-dithiobenzothiazole, cyclohexylbenzothiazole sulfenamide, andbutylbenzothiazole sulfonamide may be used, for example, but it is notlimited to or by them.

And, common stabilizer for polymerization reaction or resins may be usedas the stabilizer unlimitedly.

Meanwhile, during the polymerization reaction, a polymerizationinhibitor may be added thereto at the time when the polymerization issomewhat progressed. At this time, any polymerization inhibitor whichcan terminate the polymerization by eliminating iodine group included inthe polymerized polymer can be used without particular limitation.Specifically, one or more compounds selected from the group consistingof diphenyl suldife, diphenyl ether, diphenyl, benzophenone,dibenzothiazole disulfide, monoiodoaryl compound, benzothiazoles,benzothiazolesulfenamides, thiurams, dithiocarbamates, and diphenyldisulfide may be used.

More preferably, the polymerization inhibitor may be one or morecompounds selected from the group consisting of iodobiphenyl,iodophenol, iodoaniline, iodobenzophenone, 2-mercaptobenzothiazole,2,2′-dithiobisbenzothiazole, N-cyclohexylbenzothiazole-2-sulfenamide,2-morpholinothiobenzothiazole,N,N-dicyclohexylbenzothiazole-2-sulfenamide, tetramethylthiurammonosulfide, tetramethylthiuram disulfide, zinc dimethyldithiocarbamate,zinc diethyldithiocarbamate, and diphenyl disulfide may be used.

Meanwhile, the time of adding the polymerization inhibitor may bedetermined by considering the molecular weight of the polyarylenesulfide to be polymerized finally. For example, the inhibitor may beadded at the time of that about 70 to 100 wt % of the diiodoaromaticcompound included in the initial reactant are reacted and exhausted.

And, the polymerization reaction may be carried out in any conditionwhich can initiate the polymerization of the reactants including thediiodoaromatic compound and sulfur element. For example, thepolymerization reaction may be carried out in a temperature-rising andpressure-reducing reaction condition. At this time, the condition may becarried out for about 1 to 30 hrs while varying the temperature andpressure condition from the initial reaction condition of about 180 to250° C. and about 50 to 450 torr to the final reaction condition ofabout 270 to 350° C. and about 0.001 to 20 torr. For more concreteexample, the polymerization reaction may be carried out with the finalreaction condition of about 280 to 300° C. and 0.1 to 0.5 torr.

Meanwhile, the preparation method of the polyarylene sulfide accordingto another embodiment may further include the step of melt-compoundingthe reactants including the diiodoaromatic compound and sulfur elementbefore the polymerization reaction. The condition of themelt-compounding is not limited as long as all of the reactants aremelted and compounded, and for example, the process may be carried outat the temperature of about 130° C. to 200° C., or about 160° C. to 190°C.

Like this, by carrying out the melt-compounding step before thepolymerization reaction, it is possible to carry out succeedingpolymerization reaction more easily.

Furthermore, in the preparation method of polyarylene sulfide accordingto another embodiment, the polymerization reaction may be carried out inthe presence of a nitrobenzene-based catalyst. And, when themelt-compounding step is carried out before the polymerization reactionas disclosed above, the catalyst may be added in the melt-compoundingstep. As the nitrobenzene-based catalyst, 1,3-diiodo-4-nitrobenzene, or1-iodo-4-nitrobenzene may be used but it is not limited to or by them.

According to still another embodiment of the invention, a shaped articleincluding the polyarylene sulfide of above embodiment is provided. Theshaped article may solely consist of the polyarylene sulfide or mayfurther include other polymer materials and/or reinforcements/fillers.The polyarylene sulfide shows excellent compatibility with other polymermaterials and/or reinforcements/fillers, and makes it possible toprovide a resin composition or a shaped article having superiorproperties by being mixed (for example, compounded) with them. At thistime, the polymer materials and/or reinforcements/fillers which can becompounded with the polyarylene sulfide are same as disclosed above.

Such shaped article may include about 10 to 99 weight % or about 50 to90 weight % of the polyarylene sulfide and about 1 to 90 weight % orabout 10 to 50 weight % of one or more components selected from thegroup consisting of thermoplastic resin, thermoplastic elastomers, andfillers. And, by shaping the resin composition satisfying above contentrange with a method such as biaxial extrusion, the shaped article havingexcellent properties and applicable to various uses can be obtained.

The shaped article of still another embodiment may be various shapes offilm, sheet, fiber, and the like. And, the shaped article may be aninjection molded article, an extruded article, or a blown article. Inthe injection molding process, the mold temperature may be about 50° C.or more, about 60° C. or more, or about 80° C. or more in the aspect ofcrystallization, and the temperature may be about 190° C. or less, about170° C. or less, or about 160° C. or less in the aspect of deformationof specimen.

And, if the shaped article is a film or a sheet, it may be made into anundrawn, a uniaxially drawn, or a biaxially drawn film or sheet. If itis a fiber, it may be made into an undrawn, a drawn, or an ultradrawnfiber, and it may be used to a fabric, a knit, a nonwoven (spunbond,meltblown, or staple), a rope, or a net.

Such shaped articles may be used to electric & electronic parts such ascomputer parts, architectural elements, car parts, machine parts, dailynecessities, coating parts to which chemical materials contact,industrial chemical resistant fiber, and the like.

In the present invention, further details besides the disclosure abovemay be added and subtracted with necessity, and they are not limitedparticularly in the present invention.

Effects of the Invention

The present invention can provide a melt-polymerized polyarylene sulfidehaving excellent compatibility with other polymer materials orreinforcements/fillers because of carboxyl group or amine group includedat the end of the main chain.

Such polyarylene sulfide can exhibit excellent properties optimized tovarious uses and excellent properties unique to the polyarylene sulfideby being compounded with other various polymer materials or fillers.

Therefore, such polyarylene sulfide can be applied to various usesincluding the use of compounding, and can exhibit excellent propertiesand effects.

DETAILED DESCRIPTION OF THE EMBODIMENT

Hereinafter, preferable examples are presented for understanding thepresent invention. However, the following examples are only forillustrating the present invention and the present invention is notlimited to or by them.

Example 1: Synthesis of Polyarylene Sulfide Including Carboxyl Group orAmine Group at the End of the Main Chain

After completely melting and mixing the reactant including 5,130 g ofp-diiodobenzene (p-DIB), 450 g of sulfur, and 4 g of1,3-diiodo-4-nitrobenzene as a reaction initiator in a 5 L reactorequipped with a thermocouple capable of measuring the inside temperatureof the reactor and a vacuum line for nitrogen purging and vacuumizing byheating the same to 180° C., the polymerization reaction was proceededby carrying out temperature-rising and pressure reducing step by stepfrom the initial reaction condition of 220° C. and 350 torr to the finalreaction temperature of 300° C. and the pressure of 1 torr or less. Whenthe polymerization reaction was proceeded 80% (the proceeding degree ofthe polymerization reaction was identified by the relative viscosityratio [(present viscosity/target viscosity)*100%], and the presentviscosity was measured with a viscometer after taking a sample from thereactor where the polymerization reaction was progressing), 25 g of2,2′-dithiobisbenzothiazole was added thereto as a polymerizationinhibitor and the reaction was carried out for 1 hr. Subsequently, afteradding 51 g of 4-iodobenzoic acid thereto when the reaction wasproceeded 90% and progressing the reaction under nitrogen circumstancefor 10 mins, the reaction was further progressed with slowly vacuumizingto 0.5 torr or less for 1 hr, and terminated. By this, the polyarylenesulfide resin having carboxyl group or amine group at the end of themain chain was synthesized. The final resin obtained by the reaction wasprepared into pellets by using a small strand cutter.

The polyarylene sulfide resin of Example 1 was analyzed by FT-IRspectroscopy. At this time, the carboxyl group peak was recognized atabout 1600 to 1800 cm⁻¹ in the spectrum. It was also recognized that therelative height intensity of the peak at about 1600 to 1800 cm⁻¹ wasabout 3.4% when the height intensity of the ring stretch peak shown atabout 1400 to 1600 cm⁻¹ was assumed as 100%.

Example 2: Synthesis of Polyarylene Sulfide Including Carboxyl Group orAmine Group at the End of the Main Chain

After completely melting and mixing the reactant including 5,130 g ofp-diiodobenzene (p-DIB), 450 g of sulfur, and 4 g of1,3-diiodo-4-nitrobenzene as a reaction initiator in a 5 L reactorequipped with a thermocouple capable of measuring the inside temperatureof the reactor and a vacuum line for nitrogen purging and vacuumizing byheating the same to 180° C., the polymerization reaction was proceededby carrying out temperature-rising and pressure reducing step by stepfrom the initial reaction condition of 220° C. and 350 torr to the finalreaction temperature of 300° C. and the pressure of 1 torr or less. Whenthe polymerization reaction was proceeded 80% (the proceeding degree ofthe polymerization reaction was identified by the relative viscosityratio [(present viscosity/target viscosity)*100%], and the presentviscosity was measured with a viscometer after taking a sample from thereactor where the polymerization reaction was progressing), 25 g of2,2′-dithiobisbenzothiazole was added thereto as a polymerizationinhibitor and the reaction was carried out for 1 hr. Subsequently, afteradding 51 g of 4-iodoaniline thereto when the reaction was proceeded 90%and progressing the reaction under nitrogen circumstance for 10 mins,the reaction was further progressed with slowly vacuumizing to 0.5 torror less for 1 hr, and terminated. By this, the polyarylene sulfide resinhaving carboxyl group or amine group at the end of the main chain wassynthesized. The final resin obtained by the reaction was prepared intopellets by using a small strand cutter.

The polyarylene sulfide resin of Example 2 was analyzed by FT-IRspectroscopy. At this time, the amine group peak was recognized at about3300 to 3500 cm⁻¹ in the spectrum. It was also recognized that therelative height intensity of the peak at about 3300 to 3500 cm⁻¹ wasabout 1.4% when the height intensity of the ring stretch peak shown atabout 1400 to 1600 cm⁻¹ was assumed as 100%.

Example 3: Synthesis of Polyarylene Sulfide Including Carboxyl Group orAmine Group at the End of the Main Chain

After completely melting and mixing the reactant including 5,130 g ofp-diiodobenzene (p-DIB), 450 g of sulfur, and 4 g of1,3-diiodo-4-nitrobenzene as a reaction initiator in a 5 L reactorequipped with a thermocouple capable of measuring the inside temperatureof the reactor and a vacuum line for nitrogen purging and vacuumizing byheating the same to 180° C., the polymerization reaction was proceededby carrying out temperature-rising and pressure reducing step by stepfrom the initial reaction condition of 220° C. and 350 torr to the finalreaction temperature of 300° C. and the pressure of 1 torr or less. Whenthe polymerization reaction was proceeded 80% (the proceeding degree ofthe polymerization reaction was identified by the relative viscosityratio [(present viscosity/target viscosity)*100%], and the presentviscosity was measured with a viscometer after taking a sample from thereactor where the polymerization reaction was progressing), 25 g of2,2′-dithiobisbenzothiazole was added thereto as a polymerizationinhibitor and the reaction was carried out for 1 hr. Subsequently, afteradding 25 g of 4-iodobenzoic acid thereto when the reaction wasproceeded 90% and progressing the reaction under nitrogen circumstancefor 10 mins, the reaction was further progressed with slowly vacuumizingto 0.5 torr or less for 1 hr, and terminated. By this, the polyarylenesulfide resin having carboxyl group or amine group at the end of themain chain was synthesized. The final resin obtained by the reaction wasprepared into pellets by using a small strand cutter.

The polyarylene sulfide resin of Example 3 was analyzed by FT-IRspectroscopy. At this time, the carboxyl group peak was recognized atabout 1600 to 1800 cm⁻¹ in the spectrum. It was also recognized that therelative height intensity of the peak at about 1600 to 1800 cm⁻¹ wasabout 2.1% when the height intensity of the ring stretch peak shown atabout 1400 to 1600 cm⁻¹ was assumed as 100%.

Example 4: Synthesis of Polyarylene Sulfide Including Carboxyl Group orAmine Group at the End of the Main Chain

After completely melting and mixing the reactant including 5,130 g ofp-diiodobenzene (p-DIB), 450 g of sulfur, and 4 g of1,3-diiodo-4-nitrobenzene as a reaction initiator in a 5 L reactorequipped with a thermocouple capable of measuring the inside temperatureof the reactor and a vacuum line for nitrogen purging and vacuumizing byheating the same to 180° C., the polymerization reaction was proceededby carrying out temperature-rising and pressure reducing step by stepfrom the initial reaction condition of 220° C. and 350 torr to the finalreaction temperature of 300° C. and the pressure of 1 torr or less. Whenthe polymerization reaction was proceeded 80% (the proceeding degree ofthe polymerization reaction was identified by the relative viscosityratio [(present viscosity/target viscosity)*100%], and the presentviscosity was measured with a viscometer after taking a sample from thereactor where the polymerization reaction was progressing), 25 g of2,2′-dithiobisbenzothiazole was added thereto as a polymerizationinhibitor and the reaction was carried out for 1 hr. Subsequently, afteradding 25 g of 4-iodoaniline thereto when the reaction was proceeded 90%and progressing the reaction under nitrogen circumstance for 10 mins,the reaction was further progressed with slowly vacuumizing to 0.5 torror less for 1 hr, and terminated. By this, the polyarylene sulfide resinhaving carboxyl group or amine group at the end of the main chain wassynthesized. The final resin obtained by the reaction was prepared intopellets by using a small strand cutter.

The polyarylene sulfide resin of Example 4 was analyzed by FT-IRspectroscopy. At this time, the amine group peak was recognized at about3300 to 3500 cm⁻¹ in the spectrum. It was also recognized that therelative height intensity of the peak at about 3300 to 3500 cm⁻¹ wasabout 1.1% when the height intensity of the ring stretch peak shown atabout 1400 to 1600 cm⁻¹ was assumed as 100%.

Example 5: Synthesis of Polyarylene Sulfide Including Carboxyl Group orAmine Group at the End of the Main Chain

After completely melting and mixing the reactant including 5,130 g ofp-diiodobenzene (p-DIB), 450 g of sulfur, and 4 g of1,3-diiodo-4-nitrobenzene as a reaction initiator in a 5 L reactorequipped with a thermocouple capable of measuring the inside temperatureof the reactor and a vacuum line for nitrogen purging and vacuumizing byheating the same to 180° C., the polymerization reaction was proceededby carrying out temperature-rising and pressure reducing step by stepfrom the initial reaction condition of 220° C. and 350 torr to the finalreaction temperature of 300° C. and the pressure of 1 torr or less. Whenthe polymerization reaction was proceeded 80% (the proceeding degree ofthe polymerization reaction was identified by the relative viscosityratio [(present viscosity/target viscosity)*100%], and the presentviscosity was measured with a viscometer after taking a sample from thereactor where the polymerization reaction was progressing), 25 g of2,2′-dithiobisbenzothiazole was added thereto as a polymerizationinhibitor and the reaction was carried out for 1 hr. Subsequently, afteradding 51 g of 2,2′-dithiodibenzoic acid thereto when the reaction wasproceeded 90% and progressing the reaction under nitrogen circumstancefor 10 mins, the reaction was further progressed with slowly vacuumizingto 0.5 torr or less for 1 hr, and terminated. By this, the polyarylenesulfide resin having carboxyl group or amine group at the end of themain chain was synthesized. The final resin obtained by the reaction wasprepared into pellets by using a small strand cutter.

The polyarylene sulfide resin of Example 5 was analyzed by FT-IRspectroscopy. At this time, the carboxyl group peak was recognized atabout 1600 to 1800 cm⁻¹ in the spectrum. It was also recognized that therelative height intensity of the peak at about 1600 to 1800 cm⁻¹ wasabout 3.2% when the height intensity of the ring stretch peak shown atabout 1400 to 1600 cm⁻¹ was assumed as 100%.

Example 6: Synthesis of Polyarylene Sulfide Including Carboxyl Group orAmine Group at the End of the Main Chain

After completely melting and mixing the reactant including 5,130 g ofp-diiodobenzene (p-DIB), 450g of sulfur, and 4 g of1,3-diiodo-4-nitrobenzene as a reaction initiator in a 5 L reactorequipped with a thermocouple capable of measuring the inside temperatureof the reactor and a vacuum line for nitrogen purging and vacuumizing byheating the same to 180° C., the polymerization reaction was proceededby carrying out temperature-rising and pressure reducing step by stepfrom the initial reaction condition of 220° C. and 350 torr to the finalreaction temperature of 300° C. and the pressure of 1 torr or less. Whenthe polymerization reaction was proceeded 80% (the proceeding degree ofthe polymerization reaction was identified by the relative viscosityratio [(present viscosity/target viscosity)*100%], and the presentviscosity was measured with a viscometer after taking a sample from thereactor where the polymerization reaction was progressing), 25 g of2,2′-dithiobisbenzothiazole was added thereto as a polymerizationinhibitor and the reaction was carried out for 1 hr. Subsequently, afteradding 51 g of 4,4′-dithiodianiline thereto when the reaction wasproceeded 90% and progressing the reaction under nitrogen circumstancefor 10 mins, the reaction was further progressed with slowly vacuumizingto 0.5 torr or less for 1 hr, and terminated. By this, the polyarylenesulfide resin having carboxyl group or amine group at the end of themain chain was synthesized. The final resin obtained by the reaction wasprepared into pellets by using a small strand cutter.

The polyarylene sulfide resin of Example 6 was analyzed by FT-IRspectroscopy. At this time, the amine group peak was recognized at about3300 to 3500 cm⁻¹ in the spectrum. It was also recognized that therelative height intensity of the peak at about 3300 to 3500 cm⁻¹ wasabout 1.3% when the height intensity of the ring stretch peak shown atabout 1400 to 1600 cm⁻¹ was assumed as 100%.

Example 7: Synthesis of Polyarylene Sulfide Including Carboxyl Group orAmine Group at the End of the Main Chain

After completely melting and mixing the reactant including 5,130 g ofp-diiodobenzene (p-DIB), 450 g of sulfur, and 4 g of1,3-diiodo-4-nitrobenzene as a reaction initiator in a 5 L reactorequipped with a thermocouple capable of measuring the inside temperatureof the reactor and a vacuum line for nitrogen purging and vacuumizing byheating the same to 180° C., the polymerization reaction was proceededby carrying out temperature-rising and pressure reducing step by stepfrom the initial reaction condition of 220° C. and 350 torr to the finalreaction temperature of 300° C. and the pressure of 1 torr or less. Whenthe polymerization reaction was proceeded 80% (the proceeding degree ofthe polymerization reaction was identified by the relative viscosityratio [(present viscosity/target viscosity)*100%], and the presentviscosity was measured with a viscometer after taking a sample from thereactor where the polymerization reaction was progressing), 25 g of2,2′-dithiobisbenzothiazole was added thereto as a polymerizationinhibitor and the reaction was carried out for 1 hr. Subsequently, afteradding 25 g of 2,2′-dithiodibenzoic acid thereto when the reaction wasproceeded 90% and progressing the reaction under nitrogen circumstancefor 10 mins, the reaction was further progressed with slowly vacuumizingto 0.5 torr or less for 1 hr, and terminated. By this, the polyarylenesulfide resin having carboxyl group or amine group at the end of themain chain was synthesized. The final resin obtained by the reaction wasprepared into pellets by using a small strand cutter.

The polyarylene sulfide resin of Example 7 was analyzed by FT-IRspectroscopy. At this time, the carboxyl group peak was recognized atabout 1600 to 1800 cm⁻¹ in the spectrum. It was also recognized that therelative height intensity of the peak at about 1600 to 1800 cm⁻¹ wasabout 1.9% when the height intensity of the ring stretch peak shown atabout 1400 to 1600 cm⁻¹ was assumed as 100%.

Example 8: Synthesis of Polyarylene Sulfide Including Carboxyl Group orAmine Group at the End of the Main Chain

After completely melting and mixing the reactant including 5,130 g ofp-diiodobenzene (p-DIB), 450 g of sulfur, and 4 g of1,3-diiodo-4-nitrobenzene as a reaction initiator in a 5 L reactorequipped with a thermocouple capable of measuring the inside temperatureof the reactor and a vacuum line for nitrogen purging and vacuumizing byheating the same to 180° C., the polymerization reaction was proceededby carrying out temperature-rising and pressure reducing step by stepfrom the initial reaction condition of 220° C. and 350 torr to the finalreaction temperature of 300° C. and the pressure of 1 torr or less. Whenthe polymerization reaction was proceeded 80% (the proceeding degree ofthe polymerization reaction was identified by the relative viscosityratio [(present viscosity/target viscosity)*100%], and the presentviscosity was measured with a viscometer after taking a sample from thereactor where the polymerization reaction was progressing), 25 g of2,2′-dithiobisbenzothiazole was added thereto as a polymerizationinhibitor and the reaction was carried out for 1 hr. Subsequently, afteradding 25 g of 4,4′-dithiodianiline thereto when the reaction wasproceeded 90% and progressing the reaction under nitrogen circumstancefor 10 mins, the reaction was further progressed with slowly vacuumizingto 0.5 torr or less for 1 hr, and terminated. By this, the polyarylenesulfide resin having carboxyl group or amine group at the end of themain chain was synthesized. The final resin obtained by the reaction wasprepared into pellets by using a small strand cutter.

The polyarylene sulfide resin of Example 8 was analyzed by FT-IRspectroscopy. At this time, the amine group peak was recognized at about3300 to 3500 cm⁻¹ in the spectrum. It was also recognized that therelative height intensity of the peak at about 3300 to 3500 cm⁻¹ wasabout 1.0% when the height intensity of the ring stretch peak shown atabout 1400 to 1600 cm⁻¹ was assumed as 100%.

Comparative Example 1

After completely melting and mixing the reactant including 5,130 g ofp-diiodobenzene (p-DIB), 450 g of sulfur, and 4 g of1,3-diiodo-4-nitrobenzene as a reaction initiator in a 5 L reactorequipped with a thermocouple capable of measuring the inside temperatureof the reactor and a vacuum line for nitrogen purging and vacuumizing byheating the same to 180° C., the polymerization reaction was proceededby carrying out temperature-rising and pressure reducing step by stepfrom the initial reaction condition of 220° C. and 350 torr to the finalreaction temperature of 300° C. and the pressure of 1 torr or less. Whenthe polymerization reaction was proceeded 80% (the proceeding degree ofthe polymerization reaction was identified by the relative viscosityratio [(present viscosity/target viscosity)*100%], and the presentviscosity was measured with a viscometer after taking a sample from thereactor where the polymerization reaction was progressing), 25 g of2,2′-dithiobisbenzothiazole was added thereto as a polymerizationinhibitor and the reaction was progressed under nitrogen circumstancefor 10 mins, and the reaction was further progressed with slowlyvacuumizing to 0.5 torr or less and terminated when the viscosityreached the target viscosity. By this, the polyarylene sulfide resinhaving neither carboxyl group nor amine group at the end of the mainchain was synthesized. The final resin obtained by the reaction wasprepared into pellets by using a small strand cutter.

The polyarylene sulfide resin of Comparative Example 1 was analyzed byFT-IR spectroscopy. At this time, it was recognized that there wasneither carboxyl group peak nor amine group peak at about 1600 to 1800cm⁻¹ or about 3300 to 3500 cm⁻¹ in the spectrum.

Comparative Example 2

Product name Z200 of DIC Co., Ltd. in which the polyarylene sulfide madeby Macallum process was compounded with an elastomer was used asComparative Example 2.

Experimental Example 1: Evaluation on Basic Properties of PolyaryleneSulfide

The properties of polyarylene sulfides of Examples 1 to 8 andComparative Example 1 were evaluated by the following methods:

Melting Temperature (Tm)

By using a differential scanning calorimeter (DSC), after elevating thetemperature of the specimen from 30° C. to 320° C. with a scanning speedof 10° C./min and cooling to 30° C., the melting temperature wasmeasured while elevating the temperature from 30° C. to 320° C. againwith a scanning speed of 20° C./min.

Number Average Molecular Weight (Mn) and Polydispersity Index (PDI)

After dissolving the polyarylene sulfide in 1-chloronaphthalene at 250°C. for 25 minutes with stirring so as to be 0.4 wt % solution, thepolyarylene sulfide was divided in order in the column of a hightemperature gel permeation chromatography (GPC) system (210° C.) byflowing the solution with the flow rate of 1 mL/min, and the intensitycorresponding to the molecular weight of the divided polyarylene sulfidewas measure by using a RI detector. After making a calibration line witha standard specimen (polystyrene) of which the molecular weight wasknown, the relative number average molecular weight (Mn) andpolydispersity index (PDI) of the measure sample was calculated.

Melt Viscosity (Poise)

The melt viscosity (hereinafter, ‘M.V.’) was measured at 300° C. byusing a rotating disk viscometer. In frequency sweep measuring method,angular frequency was measured from 0.6 to 500 rad/s, and the viscosityat 1.84 rad/s was defined as the melt viscosity (M.V.).

The properties measured according to above methods are listed in thefollowing Table 1:

TABLE 1 Number Melting Average Polydispersity Melt temperature MolecularIndex Viscosity Classification (° C.) Weight (PDI) (Poise) Example 1278.6 17,667 2.9 2,940 Example 2 278.3 17,614 2.9 2,200 Example 3 278.817,435 2.8 2,830 Example 4 278.6 17,224 2.8 2,770 Example 5 277.5 17,3382.9 2,350 Example 6 277.7 17,152 2.9 2,930 Example 7 278.3 17,531 2.82,470 Example 8 278.7 17,582 2.8 2,530 Comparative 280.5 17,267 2.82,420 Example 1

Experimental Example 2: Evaluation on Mechanical Properties ofPolyarylene Sulfide

The mechanical properties of polyarylene sulfides of Examples 1 to 8 andComparative Example 1 were evaluated by the following methods:

Tensile Strength and Elongation

The tensile strength and the elongation of the polyarylene sulfidespecimens prepared according to Examples 1 to 8 and Comparative Example1 were measured according to ASTM D 638 method.

Flexural Strength

The flexural strength of the polyarylene sulfide specimens preparedaccording to Examples 1 to 8 and Comparative Example 1 were measuredaccording to ASTM D 790 method.

Impact Strength (Izod)

The impact strength of the polyarylene sulfide specimens preparedaccording to Examples 1 to 8 and Comparative Example 1 was measuredaccording to ASTM D 256 method.

The mechanical properties measured according to above methods are listedin the following Table 2:

TABLE 2 Impact Tensile Flexural Strength Strength Elongation Strength(J/m, Classification (kgf/cm²) (%) (kgf/cm²) Notched) Example 1 612 2.21,430 17 Example 2 602 1.2 1,422 20 Example 3 622 2.1 1,433 18 Example 4614 1.3 1,442 17 Example 5 628 2.2 1,455 18 Example 6 605 1.2 1,428 17Example 7 611 2.3 1,435 17 Example 8 618 1.3 1,447 19 Comparative 6051.2 1,453 19 Example 1

The specimens were prepared by compounding the polyarylene sulfide ofExamples 1 to 8 and Comparative Example 1 with other componentsaccording to the following methods:

Compounding of Polyarylene Sulfide and Glass Fiber (GF)

After drying the polymerized resin, the compounding was carried out witha small twin-screw extruder under the condition of the extrusion dietemperature of 300° C. and the screw speed of 200 rpm while adding 40parts by weight of glass fiber to 60 parts by weight of the resin.

Compounding of Polyarylene Sulfide and Elastomer

The mixing extrusion was carried out under the condition of theextrusion die temperature of 300° C. and the screw speed of 200 rpmwhile adding 10 parts by weight of Lotader (Grade AX-8840, made byArkema), the elastomer, to 90 parts by weight of the resin.

The mechanical properties of the compounded specimens were evaluated bythe same way as the polyarylene sulfide specimens and are listed in thefollowing Table 3. Furthermore, the properties of the specimen ofComparative Example 2, a commercialized compounded specimen, arecompared with Examples and Comparative Example 1 in the following Table3:

TABLE 3 Impact Tensile Flexural Strength Strength Elongation Strength(J/m, Classification (kgf/cm²) (%) (kgf/cm²) Notched) Example 1 + 58325.2 1,030 54 Elastomer 10% Example 2 + 1,750 1.8 2,440 85 GF 40%Example 3 + 577 20.5 1,010 48 Elastomer 10% Example 4 + 1,740 1.8 2,40083 GF 40% Example 5 + 564 24.3 1,010 52 Elastomer 10% Example 6 + 1,7701.8 2,480 86 GF 40% Example 7 + 568 18.7 1,005 45 Elastomer 10% Example8 + 1,750 1.8 2,420 82 GF 40% Comparative 556 2.5 950 17 Example 1 +Elastomer 10% Comparative 1,700 1.7 2,300 77 Example 1 + GF 40%Comparative 660 15.7 940 76 Example 2

According to Tables 2 and 3, it was recognized that the elongation waselevated about 10 times from about 2.2% to about 25.2 and the impactstrength was elevated about 3 times from about 17 J/m to about 54 J/m bycompounding the polyarylene sulfide of Example 1 of which carboxyl groupis introduce to the end of the main chain with the thermoplasticelastomer. And, it was recognized that the tensile strength was largelyelevated from about 602 kgf/cm² to about 1750 kgf/cm² by compounding thepolyarylene sulfide of Example 2 of which amine group is introduced tothe end group of the main chain with glass fiber. Therefore, it can beknown from the properties elevated by such compounding that thepolyarylene sulfides of Examples can show good compatibility with othervarious polymer materials or fillers, and consequently can exhibitexcellent synergistic effects.

On the other hand, it was recognized that the polyarylene sulfide ofComparative Example 1 was inferior in the compatibility with otherpolymer materials or fillers and the synergistic effects caused bycompounding was not so big.

Furthermore, the compounded specimen of Comparative Example 2 was acommercialized specimen prepared by compounding the polyarylene sulfidewhich was obtained by Macallum process and was known to be good in thecompatibility with other polymer materials and several % of elastomer.However, such compounded specimen of Comparative Example 2 also showednot enough elongation improvement by compounding with elastomer, incomparison with Examples, and it seems to have the problems(deterioration in processability and workability due to the powder form)of polyarylene sulfide obtained by Macallum process.

1-19. (canceled)
 20. A method of preparing a polyarylene sulfide,including: melt-polymerizing a reactant including a diiodoaromaticcompound and elemental sulfur; and adding a compound having carboxylgroup while carrying out the melt-polymerization, wherein the compoundhaving carboxyl group is added thereto when the degree of thepolymerization reaction is progressed 90% or more, wherein the degree ofpolymerization reaction is determined by the ratio of present viscosityto target viscosity.
 21. The method of claim 20, wherein in thepolyarylene sulfide, at least part of end groups of the main chain iscarboxyl group (—COOH), and the remainder of the end groups is iodinegroup or unsubstituted aryl group.
 22. The method of claim 20, whereinan FT-IR spectrum of the polyarylene sulfide shows a first peak between1400 and 1600 cm⁻¹ and a second peak between 1600 and 1800 cm⁻¹, whereina height intensity of the second peak is between about 0.5% and about10% of a height intensity of the first peak.
 23. The method of claim 20,wherein the compound having carboxyl group includes one or morecompounds selected from the group consisting of 2-iodobenzoic acid,3-iodobenzoic acid, 4-iodobenzoic acid, and 2,2′-dithiobenzoic acid. 24.The method of claim 20, wherein the compound having carboxyl group isadded thereto in the amount of 0.0001 to 5 parts by weight, based on 100parts by weight of the diiodoaromatic compound.
 25. The method of claim20, wherein the diiodoaromatic compound is one more compounds selectedfrom the group consisting of diiodobenzene, diiodonaphthalene,diiodobiphenyl, diiodobisphenol, and diiodobenzophenone.
 26. The methodof claim 20, wherein the melt-polymerization is carried out for 1 to 30hours by varying the temperature and pressure from the initial reactioncondition of 180 to 250° C. and 50 to 450 torr to the final reactioncondition of 270 to 350° C. and 0.001 to 20 torr.
 27. The method ofclaim 20, further including melt-mixing the reactant including thediiodoaromatic compound and sulfur element, before themelt-polymerization.